Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2018
Date : August 28, 2018 - August 31, 2018
Oil dampers have been widely used for vibration suppression of vehicles, buildings structures and other devices. Despite being used for a long time, it is indispensable to experiment to know exactly the damping performance of this oil damper. The reason is that the flow of hydraulic fluid in the cylinder is complicated and the magnitude of the pressure loss caused by the convective vortex generated around the piston cannot be accurately estimated by the computer. Many exiting design formals of the oil damper had considerable different from the experimental value because the influences of the convection vortex were ignored. On the previous report, the authors estimated exactly the influence of the convective vortex of an oil damper which has an annular clearance between the piston and cylinder as a flow passage of oil using a numerical analysis of the fluid, and had obtained the calculation results which were very close to the experimental values. On this report, this calculation method was applied to another types of oil damper, that is, a damper having a circular small hole in the piston and a damper having a bypass flow passage in the cylinder wall. Because it is not a good method to divide the fluid region in these dampers into the computational grids by a unified method, we have used the overset grid method.
